The present invention relates generally to cooling devices and, more particularly, to cooling devices for removing heat from an integrated circuit devices.
Integrated circuit devices are increasingly being used in modern electronic applications. One prevalent example is the computer. The central processing unit or units of most computers, including personal computers, is constructed from an integrated circuit device.
During normal operation, integrated circuit devices generate significant amounts of heat. If this heat is not continuously removed, the integrated circuit device may overheat, resulting in damage to the device and/or a reduction in operating performance. In order to avoid such overheating, integrated circuit cooling devices are often used in conjunction with integrated circuit devices.
One such cooling device is a fan assisted heat sink cooling device. In such a device, a heat sink is formed of a material, such as aluminum, which readily conducts heat. The heat sink is usually placed on top of and in contact with the integrated circuit device. Due to this contact, heat generated by the integrated circuit is conducted into the heat sink and away from the integrated circuit.
The heat sink may include a plurality of cooling fins in order to increase the surface area of the heat sink and, thus, maximize the transfer of heat from the heat sink device into the surrounding air. In this manner, the heat sink draws heat away from the integrated circuit and transfers the heat into the surrounding air.
In order to enhance the cooling capacity of such a heat sink device, an electrically powered fan is often mounted on top of the heat sink. In operation, the fan causes air to move over and around the fins of the heat sink device, thus cooling the fins by enhancing the transfer of heat from the fins into the ambient air.
Over the years, as the power of integrated circuit devices has increased, so has the amount of heat generated by these devices. In order to adequately cool these higher powered integrated circuit devices, integrated circuit cooling devices with greater cooling capacities are required.
Conventionally, the cooling capacity of fan assisted heat sink cooling devices has been increased by making the devices larger. Specifically, cooling devices are often made larger by the incorporation of larger heat sinks and larger fans. This increase in size, however, has been found to present a problem. Increasing the size of the cooling device in a vertical direction (i.e. in a direction transverse to the orientation of the integrated circuit device) is often a problem because of the limited envelope available in many applications, such as in the computer case of a desktop personal computer. This is an even greater problem because, in most situations, a fairly substantial clearance area is required between the fan opening and the computer case to allow adequate airflow into or out of the fan.
Increasing the size of the cooling device in a horizontal direction (i.e. in a direction parallel to the orientation of the circuit board) is also often a problem because this limits the number of integrated circuit devices (and other electronic devices) which may be incorporated into the computer case.
Another problem with fan assisted heat sink cooling devices is the noise generated by the fans, particularly in situations where larger fans are used to achieve increased cooling capacity. This is particularly a problem in desktop computers where a user is commonly in close proximity to the machine. The problem is further aggravated in situations where multiple integrated circuit devices, and, thus, multiple cooling devices, are mounted in the same computer case, as occurs in many high power computers.
Thus, it would be generally desirable to provide an apparatus which overcomes these problems associated with fan assisted heat sink devices.
The present invention is directed to a fan assisted heat sink cooling device primarily for cooling integrated circuits during operation.
The cooling device is provided with a heat sink assembly that also forms the housing surrounding the fan. In this manner, the vertical size of the cooling device is minimized. The housing is constructed of a plurality of cooling vanes which have elongated openings therebetween allowing air to pass between and cool the vanes.
The cooling device is also designed to generate significantly less noise while operating. To accomplish this, the cooling vanes are angled in an approximately opposite manner to the angle of the fan blades. It has been found that this configuration significantly reduces the noise generated by the cooling device.
The configuration of the cooling device causes it to operated in an extremely efficient manner. Because the fan housing is constructed from a series of vanes, air is caused to enter the housing through the housing wall as well as from the open top of the housing. Accordingly, the cooling device is able to operate with a much smaller overhead clearance. Also, air being exhausted from the cooling device is caused to pass over the housing vanes a second time, thus further enhancing heat dissipation.
Air is exhausted from the housing through a series of curved slots which are aligned with the orientation of the fan blades. This arrangement results in a highly efficient air flow path for increased cooling device efficiency.
The heat sink assembly may be integrally formed to prevent heat conductance losses ordinarily associated with joints. A large mass of heat conductive material is provided in the heat sink assembly immediately adjacent the integrated circuit device to enhance heat flow from the integrated circuit device into the heat sink.